Abstract

We propose and theoretically investigate a novel operating regime of femtosecond Kerr-lens mode-locked solid-state lasers that avoids group-velocity dispersion compensation by use of a nonresonant semiconductor plate in the focused resonator section that provides an overall negative nonlinear refractive index per round trip. The saturable loss of the laser resonator with an effective self-defocusing nonlinearity is derived from a generalized ABCD matrix formalism, and the correspondingly calculated steady-state pulse parameters show that a Kerr-lens mode-locked laser with an overall negative nonlinear refractive index generates stable femtosecond pulses without any dispersion compensation.

Figures (3)

(a) Saturable-aperture loss coefficient γa1 over the normalized distance of focusing mirrors M3,4,ξ = (a + b + e)/f, and the normalized separation of the laser crystal from mirror M4, b/f. (b) Same as in (a) but for the overall SPM parameter κ.